Proposal Information for 2006A-0127

Title: Calibration of Spectral Modeling Techniques for Determining Fundamental Properties of Young Stars

Abstract:
Current models of protostellar evolution may be correct but do not
yet have a strong underpinning of observational support. The most
critical missing data are measured masses for objects with different
surface temperatures and luminosities. As with main sequence and post
main sequence stars, these masses must come from orbital determinations
for binaries. To date, the number of pre-main-sequence (PMS) stars with
masses determined directly from orbital motion are too few to
sufficiently cover the region of the H-R diagram occupied by low mass
PMS stars. With emergence of sensitive high resolution near-IR
spectrometers on large telescopes, we now have the capability to measure
fundamental stellar properties from spectroscopy alone. This new
technique relies on precise fits of photospheric lines, fully resolved
in late-type PMS spectra at high resolution, matching to synthetic
spectral templates. We propose to apply this new spectral fitting
routine to a sample of PMS stars, both singles and binaries, observed
with NIRSPEC at R=18,000, in order to calibrate and apply this technique
as a reliable way to anchor PMS objects on the H-R diagram.